feat: Added listener rules support

[dmattia]

Description

Added listener rules support.

This PR adds support for creating aws_lb_listener_rule resources, with all currently supported actions and conditions from the terraform provider supported. For now, I only added support to https listeners, but adding http listener support later would be trivial.

Docs wise, I updated the REAMDE to include an example of using the listener_rule var, and also updated the example to have near-complete usage.

Motivation and Context

This repo recently added support for updating the default rule for a listener, which was awesome. This PR goes one step further, for adding rules with conditions, such as only protecting certain paths with authentication.

Fixes: #154

Breaking Changes

There are no breaking changes. Plans will be empty on upgrades to use this branch's code if users do not make any changes.

How Has This Been Tested?

I have tested some of the actions/conditions in the dev environment in my companies codebase. I also updated the complete alb example to use almost every actions/condition type and ensured that terraform validate came up clean.

[antonbabenko]

Hi @dmattia !

At first look, it looks very good to me, but I don't have a lot of time to review it and verify examples.

@rriveramdz could you please take a look at this? In particular, I wonder if there are any differences in code between this PR and your recent PR where you added actions.

Thanks guys!

[rriveramdz]

Hi @dmattia.

This looks really great. I guess the only thing I think should be added is to add in README and examples that there's a maximum of two actions per load balancer rule, so that users have this clear.

[dmattia]

Awesome, thanks for the quick reviews both of you!

I updated the README to include a warning about how to use the actions properly on load balancer rules.

[dmattia]

Just updated the branch. Please let me know if there's anything else I can do

[limratechnologies]

@dmattia Thanks for this, looks awesome.

Tried running the code, I'm getting the below error, Am I doing something wrong?

Error: Invalid index

  on ../../../../terraform-aws-alb-module/alb.tf line 388, in resource "aws_lb_listener_rule" "https_listener_rule":
 388:         http_header_name = condition.value["http_headers"]["http_header_name"]
    |----------------
    | condition.value["http_headers"] is tuple with 1 element

The given key does not identify an element in this collection value: a number
is required.


Error: Invalid index

  on ../../../../terraform-aws-alb-module/alb.tf line 389, in resource "aws_lb_listener_rule" "https_listener_rule":
 389:         values           = condition.value["http_headers"]["values"]
    |----------------
    | condition.value["http_headers"] is tuple with 1 element

The given key does not identify an element in this collection value: a number
is required.

[dmattia]

@limratechnologies what does your condition look like? In particular, your http_headers?

[limratechnologies]

@dmattia I have used the format mentioned in the example.

terraform-aws-alb/examples/complete-alb/main.tf

Line 243 in 635fbcf

http_headers = [{

[dmattia]

Sure, I just updated a fix to the issue @limratechnologies had, and now the complete example works.

It's ready for review now

[antonbabenko]

Thanks, @dmattia and @rriveramdz !

v5.9.0 has been just released.

[github-actions]

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